C.3 Examples

Let's start off with a simple example. Suppose that you have a saturated Internet connection, shared by many users. You can use delay pools to limit the amount of bandwidth that Squid consumes on the link, thus leaving the remaining bandwidth for other applications. Use a class 1 delay pool to limit the bandwidth for all users. For example, this limits everyone to 512 Kbit/s and keeps 1 MB in reserve if Squid is idle:

 delay_pools 1 delay_class 1 1 delay_parameters 1 65536/1048576 acl All src 0/0 delay_access 1 allow All 

One of the problems with this simple approach is that some users may receive more than their fair share of the bandwidth. If you want to try something more balanced, use a class 2 delay pool that has individual buckets. Recall that the individual bucket is determined by the fourth octet of the client's IPv4 address. Thus, if you have more than a /24 subnet, you might want to use a class 3 pool instead, which gives you 65536 individual buckets. In this example, I won't use the network buckets. While the overall bandwidth is still 512 Kbit/s, each individual is limited to 128 Kbit/s:

 delay_pools 1 delay_class 1 3 delay_parameters 1 65536/1048576 -1/-1 16384/262144 acl All src 0/0 delay_access 1 allow All 

You can also use delay pools to provide different classes of service. For example, you might have important users and unimportant users. In this case, you could use two class 1 delay pools. Give the important users a higher bandwidth limit than everyone else:

 delay_pools 2 delay_class 1 1 delay_class 2 1 delay_parameters 1 65536/1048576 delay_parameters 2 10000/50000 acl ImportantUsers src 192.168.8.0/22 acl All src 0/0 delay_access 1 allow ImportantUsers delay_access 2 allow All